Pneumatic tire having wide groove having two longitudinal ribs, intermediate ribs and lateral ribs

• US 6,505,661 B1
• Filed: 08/11/2000
• Issued: 01/14/2003
• Est. Priority Date: 08/11/2000
• Status: Expired due to Fees

• Current Assignee: Sumitomo Rubber Industries Limited
• Original Assignee: Sumitomo Rubber Industries Limited
• Inventors: Nakagawa, Yoshiki, Yoshioka, Tetsuhiko
• Primary Examiner(s): Maki, Steven D.
• Application Number:
  US09/636,747
• Time in Patent Office: 886 Days
• Field of Search: 152/209.15, 152/209.18, 152/209.19, 152/209.22, 152/209.26, 152/209.28, 425/812
• US Class Current: 152/209.15
• CPC Class Codes: B60C 11/0302 directional pattern, i.e. with main rolling direction
• CPC Class Codes: B60C 11/0309 further characterised by the groove cross-section
• CPC Class Codes: B60C 11/042 further characterised by the groove cross-section
• CPC Class Codes: B60C 11/13 characterised by the groove cross-section, e.g. for buttressing or preventing stone-trapping
• CPC Class Codes: B60C 2011/1231 being shallow, i.e. sipe depth of less than 3 mm
• CPC Class Codes: B60C 2011/1361 with protrusions extending from the groove bottom

Abstract

A pneumatic tire comprises a tread portion provided with a wide groove having a bottom width of not less than 20 mm. The wide groove is provided on the groove bottom with at least one longitudinal rib extending in the longitudinal direction of the wide groove, and lateral ribs extending from the longitudinal rib towards a tread face through the groove bottom and a groove wall of the wide groove, whereby occurrence of bareness of tread rubber in the groove bottom can be prevented.

Claims

1. A pneumatic tire comprising

a wide groove having a bottom width of not less than 20 mm and disposed in a tread portion,

the wide groove provided with two longitudinal ribs, intermediate ribs and lateral ribs,

said two longitudinal ribs each extending in the longitudinal direction of the wide groove and each disposed on the groove bottom of said wide groove at a distance of from 2 to 8 mm from one of edges of the groove bottom towards the center of the wide groove, the two longitudinal ribs each having a height of 0.2 to 1.5 mm,

said intermediate ribs disposed on the groove bottom between the two longitudinal ribs and each extending from one of the two longitudinal ribs towards the other, the intermediate ribs each having a height of 0.2 to 1.5 mm,

said lateral ribs each extending from one of the two longitudinal ribs towards a tread face through the groove bottom and a groove wall of the wide groove.

2. The pneumatic tire according to claim 1, wherein the lateral ribs. extend-into the tread face.

3. The pneumatic tire according to claim 1, wherein the lateral ribs extend to spues formed in the tread face or vestiges thereof.

4. The pneumatic tire according to claim 1, wherein

said intermediate ribs are straight or V-shaped or U-shaped and are arranged in a parallel formation.

5. The pneumatic tire according to claim 4, wherein an inclination angle of each said intermediate rib is not less than 30 degrees with respect to the longitudinal direction of the wide groove.

6. The pneumatic tire according to claim 1, wherein

said intermediate ribs are straight and are arranged in a staggered V-formation.

7. A pneumatic tire according to claim 6, wherein,

each said intermediate rib extends from one of the two longitudinal ribs to the center of the groove.

8. The pneumatic tire according to claim 6, wherein an inclination angle of each said intermediate rib is not less than 30 degrees with respect to the longitudinal direction of the wide groove.

9. The pneumatic tire according to claim 1, wherein

an inclination angle of each said intermediate rib is not less than 30 degrees a with respect to the longitudinal direction of the wide groove.

10. The pneumatic tire according to claim 1, wherein each lateral rib has a height of 0.2 to 0.8 mm and a width of 0.4 to 1.6 mm.

11. The pneumatic tire according to claim 1, wherein each intermediate rib has a width of 0.8 to 3 mm and each longitudinal rib has a width of 0.4 to 3.0 mm.

12. The pneumatic tire according to claim 1, wherein each of the longitudinal ribs and lateral ribs has a rounded sectional shape, and each of the intermediate ribs has a triangular sectional shape.

13. The pneumatic tire according to claim 1, wherein the height of the intermediate ribs is not more than the height of the two longitudinal ribs.

14. The pneumatic tire according to claim 1, wherein the height of the intermediate ribs is less than the height of the two longitudinal ribs.